A method of manufacturing a honeycomb structure including a honeycomb unit includes forming a honeycomb molded body having a plurality of cells extending from a first end face to a second end face of the honeycomb molded body along a longitudinal direction of the honeycomb molded body and separated by a plurality of cell walls, placing the honeycomb molded body in a degreasing apparatus so that the first end face faces downward and the second end face faces upward, feeding introduced gas into the degreasing apparatus, degreasing the honeycomb molded body at a temperature of approximately 200° C. to approximately 400° C., and firing the degreased honeycomb molded body at a temperature of approximately 500° C. to approximately 900° C. to obtain the honeycomb unit.